cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pgtable.c (2643B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
      4 */
      5#include <linux/init.h>
      6#include <linux/export.h>
      7#include <linux/mm.h>
      8#include <asm/pgalloc.h>
      9#include <asm/pgtable.h>
     10#include <asm/tlbflush.h>
     11
     12pgd_t *pgd_alloc(struct mm_struct *mm)
     13{
     14	pgd_t *ret, *init;
     15
     16	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
     17	if (ret) {
     18		init = pgd_offset(&init_mm, 0UL);
     19		pgd_init((unsigned long)ret);
     20		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
     21		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
     22	}
     23
     24	return ret;
     25}
     26EXPORT_SYMBOL_GPL(pgd_alloc);
     27
     28void pgd_init(unsigned long page)
     29{
     30	unsigned long *p, *end;
     31	unsigned long entry;
     32
     33#if !defined(__PAGETABLE_PUD_FOLDED)
     34	entry = (unsigned long)invalid_pud_table;
     35#elif !defined(__PAGETABLE_PMD_FOLDED)
     36	entry = (unsigned long)invalid_pmd_table;
     37#else
     38	entry = (unsigned long)invalid_pte_table;
     39#endif
     40
     41	p = (unsigned long *) page;
     42	end = p + PTRS_PER_PGD;
     43
     44	do {
     45		p[0] = entry;
     46		p[1] = entry;
     47		p[2] = entry;
     48		p[3] = entry;
     49		p[4] = entry;
     50		p += 8;
     51		p[-3] = entry;
     52		p[-2] = entry;
     53		p[-1] = entry;
     54	} while (p != end);
     55}
     56EXPORT_SYMBOL_GPL(pgd_init);
     57
     58#ifndef __PAGETABLE_PMD_FOLDED
     59void pmd_init(unsigned long addr, unsigned long pagetable)
     60{
     61	unsigned long *p, *end;
     62
     63	p = (unsigned long *) addr;
     64	end = p + PTRS_PER_PMD;
     65
     66	do {
     67		p[0] = pagetable;
     68		p[1] = pagetable;
     69		p[2] = pagetable;
     70		p[3] = pagetable;
     71		p[4] = pagetable;
     72		p += 8;
     73		p[-3] = pagetable;
     74		p[-2] = pagetable;
     75		p[-1] = pagetable;
     76	} while (p != end);
     77}
     78EXPORT_SYMBOL_GPL(pmd_init);
     79#endif
     80
     81#ifndef __PAGETABLE_PUD_FOLDED
     82void pud_init(unsigned long addr, unsigned long pagetable)
     83{
     84	unsigned long *p, *end;
     85
     86	p = (unsigned long *)addr;
     87	end = p + PTRS_PER_PUD;
     88
     89	do {
     90		p[0] = pagetable;
     91		p[1] = pagetable;
     92		p[2] = pagetable;
     93		p[3] = pagetable;
     94		p[4] = pagetable;
     95		p += 8;
     96		p[-3] = pagetable;
     97		p[-2] = pagetable;
     98		p[-1] = pagetable;
     99	} while (p != end);
    100}
    101#endif
    102
    103pmd_t mk_pmd(struct page *page, pgprot_t prot)
    104{
    105	pmd_t pmd;
    106
    107	pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
    108
    109	return pmd;
    110}
    111
    112void set_pmd_at(struct mm_struct *mm, unsigned long addr,
    113		pmd_t *pmdp, pmd_t pmd)
    114{
    115	*pmdp = pmd;
    116	flush_tlb_all();
    117}
    118
    119void __init pagetable_init(void)
    120{
    121	/* Initialize the entire pgd.  */
    122	pgd_init((unsigned long)swapper_pg_dir);
    123	pgd_init((unsigned long)invalid_pg_dir);
    124#ifndef __PAGETABLE_PUD_FOLDED
    125	pud_init((unsigned long)invalid_pud_table, (unsigned long)invalid_pmd_table);
    126#endif
    127#ifndef __PAGETABLE_PMD_FOLDED
    128	pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
    129#endif
    130}